Hach Debubb User Instructions page 8

Section 5 Adjust the PRVs
Adjust the two orange pressure reducing valves (PRV) of the debubbler.
Items to collect:
• Flat-head screwdriver, small
• Allen wrench, 8 mm
• Open-end wrench, 24 mm
1. Close the two shutoff valves of the debubbler.
2. Close the seven valves in the ScrubberMonitor. Refer to
3. Open bypass valve (Q2-V2).
4. Start the flow of sample water to the debubbler. Water flows from the debubbler drain.
5. Adjust the orange pressure reducing valve (PRV) that is near the floor so that water flows out the
debubbler drain when the bottom shutoff valve is closed, but not when the bottom shutoff valve is
open as follows:
a. Use the flat-head screwdriver to remove the black cap from the PRV.
b. Use the open-end wrench to loosen the locking nut.
c. Use the Allen wrench to turn the set screw clockwise until the pressure gauge on the PRV
shows 3 bar. The flow of water from the debubbler drain stops.
d. Turn the set screw counter-clockwise until the flow of water from the debubbler drain starts
again.
e. Open the shutoff valve at the bottom of the debubbler. Make sure that the flow of water from
the debubbler drain stops. If not, adjust the set screw again.
f. Tighten the locking nut.
g. Install the black cap on the PRV.
6. Flush the external sample line as follows:
a. Open the bypass valve (Q2-V2).
b. Let the sample water flow through the bypass tubing until the water flow removes the
construction materials in the sample line.
c. Close the bypass valve (Q2-V2).
7. Open the sample inlet and outlet valves (Q2-V1 and Q2-V3). Refer to
the instrument.
8. When there is no longer air in the instrument tubing, remove the air from the sample flow cell as
follows:
a. Put a container under the vent. The vent is on the right side at the top of the ScrubberMonitor.
b. Open the vent valve (Q6-V1). Refer to
c. When water comes out of the vent, close the vent valve (Q6-V1).
9. Adjust the orange PRV that is above the instrument so that water does not flow from the top of
the debubbler when the top shutoff valve is open as follows:
a. Make sure that the shutoff valve at the top of the debubbler is closed.
b. Use the flat-head screwdriver to remove the black cap from the PRV.
c. Use the open-end wrench to loosen the locking nut.
d. Use the Allen wrench to turn the set screw fully clockwise (closed) so water cannot get past
the PRV.
e. Open the top shutoff valve of the debubbler.
f. Turn the set screw counter-clockwise until the sound of a gas leak is heard, but no water gets
past the PRV.
g. Tighten the locking nut.
h. Install the black cap on the PRV.
8 English
Figure 5.
Figure 5.
Figure 5. Water flows into